Laportea canadensis.Albert Bussewitz.New England Wild Flower Society.gobotany.newenglandwild.org (Accessed 4/2014).

Laportea canadensis is a perennial herb, 0.5-1 m tall, stems armed with stinging hairs, roots fibrous, often colonial from rhizomes, associated with VA mycorrhizas (Brundrett and Kendrick 1988). 

Leaves alternate, stalked, blade 8-15 cm long, broadly egg-shaped, hairy, veins palmate at base, pinnate above, deeply impressed, tip long-pointed, margin coarsely toothed. 

Flowers greenish, tiny, monoecious, male flowers dense, branched, in axillary clusters, female flowers in large, dense, branched, spreading clusters in upper axils longer than leaf stalks; blooms July-Aug. (Hough 1983); wind pollinated (Lovell 1918). 

Fruit dry, an achene enclosed within 2 persistent sepals; fruits Aug.-Sept. (Hough 1983). 

Wetland status: FACW. 

Frequency in NYC: Infrequent but often in large colonies. 

Origin: Native. 

Habitat: Moist woods or swamp forest edges, flood plain forests, shade tolerant. 

Nymphalis antiopa-caterpillar.en.wikipedia.org (Accessed 2/2015).

Notes: Host to larvae of the mourning cloak butterfly, Nymphalis antiopa (native to Europe (Wright 1993)); question mark butterfly, Polygonia interrogationis, and the comma butterfly, P. comma, all family Nymphalidae (Tallamy 2003; Pyle 1981).